The Yin to His Yang
by HobbitEzzie3791
Summary: Leo Valdez felt like he would forever be the seventh wheel. Then along comes a new demigod, or rather an old one who had been frozen in time by her mother, Khione. Is the "Ice Princess" really as cold and aloof as she seems? Could she be icy yin to Leo's fiery yang?
1. Chapter 1

**Chapter I**

It was a normal day at Camp Half-Blood. Well, as normal as it could be considering they had teamed up with the Romans for the first time in history and defeated Gaea only about three months ago. Needless to say, there was still some things that the demigods were working on getting fixed from the battle, and Leo Valdez was right in the middle of it.

As the head of Cabin Nine (A.K.A. Hephaestus cabin), he was unofficially in charge of most of the physical rebuilding process, though he delegated a lot to the heads of the other cabins based on who would best at fixing certain things. Apollo kids were the healers; the Ares kids were working on rebuilding the defences and armory; Annabeth Chase and some of the Athena kids were designing and drawing up blueprints for the building that were going to have to be rebuild, etc.

"Hey, Valdez, you know where the specs for the training arenas are?" Someone shouted as Leo walked by on his way to Thalia's pine.

"Um, I think Miss Architect's guys still has them," he called back. "Something about making adjustments."

"Thanks!"

Leo sent them a thumbs up. "Any time." He looked at all the bustle around him and smiled. So much to do. So much to build. As a son of Hephaestus, he loved building things, although he definitely prefered mechanics to architecture. However, all the building projects were not the reason for Leo's current excitement as he practically skipped to his destination.

His best friend, Jason Grace, along with Hazel Levesque and Frank Zhang, was arriving at camp today as part of an exchange program the two camps had set up to help foster good will and peace. Percy, Annabeth, and Nico had left a few days ago to visit Twelfth Legion and New Rome.

When he arrived at the designated meeting place, he was not surprised to find Piper, his other best friend and Jason's girlfriend, already there. "Hey there, Beauty Queen."

"Hi, Repair Boy," she winked back.

He just grinned and shoved his hands in his pockets. "Excited to see our blonde Superman again?" he teased.

"You are too!" she defended herself.

"Never said I wasn't," he answered. Just then, shouts echoed from the woods.

"Jason?" Piper called worriedly. As if answering her shout, a group of demigods burst from the tree line. Hazel and a satyr (Leo thought his name was Grover) were supporting a pale girl on either side. Jason and Frank were a few paces behind them, acting as rear guard. Three emposa out the woods and tore after the demigods.

Ah, so that's what they're running from, Leo thought. Piper ran forward to help Jason and Frank. Leo quickly took the girls right arm from Hazel and pulled it across his own shoulders. "Go help the others; we've got 'er," he said.

Leo and Grover quickedly headed for the Big House. "Medic!" The satyr shouted over his shoulder. "We need a medic over here!" Right about then, the girl, who had been doing her best to trudge between the two of them, sagged, her knees giving out. Leo looked down at noticed the bleeding gash on her forehead and the growing red spot around a tear in her white T-shirt. He quickly eased her down to the ground.

"We've got a demigod down, Solace!" Leo cried. "Get your sunshiney healer butt over here!"

"It's okay, Miss, it's okay," Grover soothed the girl, who was whimpering in pain. "You're safe now; you're gonna be fine." They girl's eyes fluttered open and revealed pale ice blue orbs filled with pain and confusion.

"No worries, _Señorita_ ," Leo said. "Solace will have you fixed up in no time flat." Her eyes wonder to him and locked onto his chocolate brown ones for a moment. Leo forgot how to breathe until her eyelids fluttered closed.

Finally, Will Solace arrived with stretcher and medical supplies. Leo and Grover backed up and let Will and two of his siblings do their thing. In moments, they had her wounds temporarily bandaged and were carrying her on the stretcher to the Big House.

Jason, Piper, Hazel, and Frank, having finished off the emposa, trudged up behind Leo, watching the medics taking away their patient.

"Is...she gonna...be...okay?" Jason gasped, still out of breath from running.

"They didn't say she wouldn't be," Leo answered.

"Leo!" Piper and Hazel gasped at the same time.

"What?" Leo shrugged innocently. "They didn't say. Honest!"

"Nah, she'll be fine, guys," Grover answered sagely. "Those Apollo kids know their stuff. She's probably be down with for campfire tomorrow night."

"Who is she?" Hazel asked.

"Yeah, what happened to you guys?" Frank added.

"First off, she wouldn't tell me her name, but I know she's a half-blood," Grover said. "She not exactly...the nicest person I've ever met."

"What do you mean?" Jason asked.

"She's not mean or rude, really...just kinda...cool. Aloof."

"And the emposa?"

"Oh, yeah, _them_ ," Grover shook his head. "Found Miss cool up near the Canada-US border. Thought we lost 'em back in Michigan, but apparently not. They caught back up with us near the New York State line. Been on the run for the last two days."

Frank winced. "Glad we happened to run in to you guys, then."

"Yeah, thanks for the help, man," Grover patted the Roman's shoulder. "Listen, I gotta give a report to Chiron. See you guys at dinner, okay?"

"Later!" The demigods chorused as Grover headed up the hill to the Big House.

Piper immediately threw her arms around Jason, causing him stumble in surprise. Leo, Frank, and Hazel chuckled at the pair.

"Easy, Beauty Queen, don't crush your Sparky knight in shining armor," the son of Hephaestus teased.

 _"Leo!"_

* * *

 ** _Author's Note: This is going to be slightly AU because Leo and Calipso are not romantically involved at all. Their relationship will be more brother/sister. Leo went back and rescued her because he loves her like a sister and could not bear to leave her alone on that island. Savy? ;)_**


	2. Chapter 2

**Chapter II**

That night around the campfire, the camper gathered to sing ridiculous songs about putting armor on (led by the Apollo cabin, of course) and make s'mores. After several songs were sung and the campfire had grown tall and turned a bright gold color, Chiron stood before the assembled demigods.

"First, I would like to welcome Praetor Frank Zhang and Hazel Levesque, and welcome back Jason Grace." Here, he gave a little bow to the Romans, who formally rose and returned the gesture amid the campers' applause. "Secondly, I want to announce the game of Capture the Flag set for tomorrow night after campfire." This announcement was met with loud cheers and applause. "Lastly, I will confirm the rumors that are flying. Yes, Grover brought us a new camper today. Unfortunately, they had a run-in with a few emposa along the way, and the half-blood was gravely injured. But, thanks to our Roman friends, she was brought to camp and the care of our best healers in time. Will, do you have a report on her condition?"

The son of Apollo stood. "Her injuries were pretty bad, but we have her on a nectar-ambrosia regement that should have her on her feet by tomorrow night or the following morning," he said. "We have also learned that she speaks only a little English; she mostly speaks French. Of course she also speaks Ancient Greek, so we were able to get that she's from Quebec and her name is Cosette."

"Thank you, Will. Hopefully, tomorrow night Cosette will be able to join us at campfire. Good night, everyone!"

Jason, Piper, Leo, Hazel, and Frank began to walk back toward the cabins.

"Well, I didn't see that one coming," Jason said.

"Didn't see what?" Piper asked.

"New girl being French Canadian," he answered. "I think Frank is about the only non-American I know."

"I'm sure Frank's happy about it, though," Hazel said, squeezing her boyfriend's hand. Frank gave a questioning look.

"Dude, she's Canadian," Leo answered. "She's one of your countrymen! Or countrywomen...however that goes..."

But I'm not from her part of Canada. I don't even speak French."

"But she's _Canadian_ ," Leo insisted.

"Whatever," Frank shrugged.

Goodnight, guys," Piper chuckled as they reached her cabin.

"Yeah, cuz you totally need your beauty sleep," Leo quipped.

"Leo!" Jason scolded. He turned to his girlfriend and kissed her cheek. "Night, _splendidis_."

"Night, Sparky," she winked. He sputtered in mock offense, but forgave her when she brushed a kiss to his lips.

Of course, their little moment was broken by a certain son of Hephestus. "Aww, geez! Get a room, people!" Leo had his eyes covered and was dramatically miming retching. Hazel had just lowered her eyes to the ground, blushing slightly, while Frank turned bright red.

"You won't be saying that when you find a girl, Leo," Piper commented.

"If is the question, Piper; not when."

"Come on, you just haven't met her yet," Jason replied encouragingly.

"Well, this metaphorical girl is taking her sweet time in making herself known," Leo sighed.

"Maybe she's shy," Hazel said. "Maybe she's the hard to get type."

"Just my luck."

"This isn't bad, Leo," Piper answered sagely. "When you find her, which you will, she will be worth the wait."

Leo shrugged. "If you say so."

"We say so," Frank quietly replied, gazing down at Hazel and squeezing her hand affectionately.

"Well, I'll see you guys in the morning," Leo said, changing the subject. "Day one with Commander Toolbelt's Camp Recovery Project starts bright and early!" He waved good bye, and headed for Cabin Nine.

·{}·{}·{}·{}·{}·

The next morning was warm with plenty of bright sun streaming down on the camp. Everyone got right to work after breakfast in the dining pavillion. Jason ended up working on the roof of the Apollo cabin, since he was comfortable with heights. Frank, as strong as an ox, brought building supplies to and from different work sites. The girls worked wherever they found a job they could manage. They all worked hard all day, stopping around four to rest up and prepare for the capture the flag game that night.

Although the tables were set up for the campers to sit according to their cabin, the Hades was empty, so Jason, Piper, Frank, and Leo sat with Hazel so she would not be alone. A few minutes after dinner had started, Will Solace came in carefully leading a pale girl to the Apollo table. He had his arm around her back, his hand gripping her elbow. His other hand held het hand as she leaned somewhat on him as they slowly shuffled across the marble floor.

Leo remembered thinking she was pale before, but everthing had happened so fast that his brain had not had time to process all the details. Pale did not even begin to cover this girl. Her skin was as white a Boread's.

 _Should she even be out of bed?_ Leo thought. _She looks half a shade of white away from death._ Her long wavy hair, neatly plaited in a french braid, was so pale blonde that it almost looked white. She wore a clean Camp Half-Blood t-shirt, which contrasted brightly with her coloring, and jeans.

"Wow, she looks more like a ghost than Nico does," Hazel said.

"Yeah, no kidding," Frank replied.

"I wonder why Will brought her down here," Piper asked. "She's clearly not strong enough to walk on her own."

"Excercize?" Leo suggested.

"Change of scenery?" Jason theorized.

Leo could not help but notice how uncomfortable she looked when Will was helping her across the room. Like she was not used to people helping her. Or maybe it was that fact that a guy was helping her. Her discomfort seemed to ease for a few minutes once he had settled her down at the table, but soon returned when several of the campers tried talking to her. Then the Stoll twin, co-councelors of the Hermes cabin went over and began talking to her too. Will was clearly trying to get them to give her some space, but to no avail.

"They're smothering her," Piper said quietly.

"Hmm?" Jason asked. He had already gone back to eating his hamburger.

"She does look rather overwhelmed," Hazel agreed.

Piper rose from the table. "I'll be right back." She went over and chased off the Stolls, then crouched so she was at the girl's eye level. They spoke for a minute, the girl's face brightening when Piper began speaking French. Piper pointed back to the Hades table, so Jason took the cue to smile and wave. Leo sent her a huge grin and thumbs up. Hazel and Frank tried to follow Jason's lead, but Frank did not know how friendly he looked considering he had just stuffed a few pieces of kung pao chicken in his mouth seconds before.

The girl looked thoughtful for a minute, then nodded to Piper. Will stood and helped the girl rise. Piper grabbed the girl's plate and cup while Will began leading the way to the Hades table. Piper walked ahead and set the plate and cup down so she could help the girl sit down. Once she was settled, Will looked at Piper, pointing to the plate.

"Please, make sure she eats all of it. She still needs to regain a lot of strength."

"Of course," Piper nodded, and Will left. "Guys, this is Cosette," she said, then pointed to each person in turn. "Jason."

He nodded with a smile. "Bon-sure."

Cosette raised a faintly amused eyebrow at him, trying to supress a slight smile. _"Bonjour, monsieur."_

"Hazel."

"Hi," Hazel waved.

"Frank."

He just nodded.

"and Leo."

"Also known as Commander Toolbelt, Admiral Valdez, and the Super-sized McShizzle!" Leo added exuberantly. "Hola!" He stuck out his hand for her to shake. She stared at him for a few moments before lightly placing her hand in his. Suddenly, he felt like he was holding the hand of a china doll. Her hand felt thin, delicate, and cold to the touch. He gave it a little shake, much more gently than he had originally planned on, before releasing it.

Throughout dinner, conversation flowed, though Cosette mostly just listened. Occasionally, she made a quiet comment in French to Piper who would translate for her.

Leo watched Cosette out of the corner of his eye. In spite of the fact that she clearly was not very strong yet, she sat up quite straight with perfect table manners: her napkin was neatly in her lap, her elbows were never on the table, she never spoke over anyone, and she even ate foods Leo thought of as finger foods, like grapes and strawberries, with utensils. She acted like...a lady. As in, she lived a big, grand house with servants and had fancy dinner parties kind of lady. But she was not showing off. She seemed to be doing it all subconsciously, like it was just part of who she was.

She was not like anybody he had met. Most demigods were pretty down-to-earth. They all fought for survival too much to be worried about stuff like perfect table manners.

As if sensing his thoughts pertained to her, Cosette met his gaze. He instantly could see the guarded look in her eyes that contrasted with the expression of polite interest on her face. She seemed to be assessing him for untrustworthiness.

 _Go ahead and judge all you want_ , he thought.

As if in answer, she raised her chin slightly, and turned her icy blue gaze away. Little did they know, that night was the start of a unconventional relationship.

* * *

 _ **Please let me know what think! Reviews are inspiration!**_


	3. Chapter 3

**Chapter III**

After dinner, Will approached the Hades table. "I should probably take Cosette back up to the Big House to rest before campfire."

"But that's pretty far from here, Will," Hazel said.

"And from the amphitheater," Piper added. "One of the cabins would be closer."

"But everyone's getting for Capture the Flag tonight," Frank commented. "Trust me there is no way to rest in a cabin bustling with war-game prep."

"She can come in my cabin," Jason volunteered.

"She can?" Will asked, surprised.

"Well, the only other relatively empty cabins are Posidon and Hades." Jason shrugged."We shouldn't go in Percy's without permission, and the Hades cabin is just creepy. No offense, Hazel."

"None taken."

"So that just leaves mine," Jason finished. "No worries, Will. Someone added an actual bunk since last time I was here."

Cosette just sat there with a confused face, unable to follow the conversation. _"Um, excusez-moi, traduction s'il vous plaît?"_

"Oh, sorry, Cosette!" Piper quickly explained what they had been talking about. The white-haired girl turned her icy eyes on Jason, as if trying to decide if she trusted him. Jason meet her gaze unflinchingly. Finally, Cosette nodded. Will began to help Cosette to her feet, and Jason jumped up to help.

The procession was slow, but they evenutally made it to the door of the white marble Zeus cabin. Piper was glad the cabins were not any farther way; Cosette was starting to look pretty tired. Ever the gentleman, Jason held the door open for the girls, while Will and Piper helped Cosette inside.

"Woah!" Leo gasped as he look up at the huge statue of Zeus that dominated the space.

"Yeah...we try to ignore it. It actually gets kinda creepy at night." Jason shrugged. He motioned them to an alcove near the back where a pristinely made bed stood. He propped the pillow against the headboard, and let the Will and Piper settle their charge on the bed.

Cosette just leaned back and closed her eyes wearily. _"Mercí,"_ she sighed.

"Your welcome," Piper answered.

"Wow, she looks tired," Frank commented softly. "Maybe she shouldn't go to campfire tonight."

"She's got an hour to rest; maybe she'll be feeling better then," Jason said.

"So, what's your story, Miss Quebec?" Leo asked. "Your Olympic parent, is it your mom or dad?"

"Shh," Piper and Hazel shushed.

"What?"

"Dude, I think she's already asleep," Will whispered.

"Seriously? That's almost as fast as Death Boy!"

"Leo!" Hazel scolded. "Don't call Nico 'Death Boy'!"

"But he sleeps like the dead! Literally!" he protested. "Besides, I let you guys call me 'Repair Boy'."

"I only call you that because you call me 'Beauty Queen'," Piper defended.

"Well, if the shoe fits, Pipes."

"Back at ya, Valdez!" Jason chuckled.

"Touché," Leo sighed.

"Thank you, Sparky," Piper grinned.

"Hey!"

Leo's grin returned. "If the shoe fits, Superman."

* * *

 _ **French translations according to Google Translate:**_

 _excusez-moi, traduction s'il vous plaît? = Excuse me, translation please?_

 _Mercí = thank you_


	4. Chapter 4

**_This chapter is dedicated to my lovely reviewer, YassauseXXX, who has been very encouraging to me. Hope you enjoy!_**

 **Chapter IV**

Cosette woke to someone gently shaking her awake. She was lying on something soft. She could not remember the last time she laid like this. Maybe she was dreaming. If she was, she really did not want to wake, because waking meant one thing: _Mother_.

"Cosette, you think you can make it to the campfire?" A feminine voice asked. "It's time to go."

Campfire? Mother and Grandfather never let there be fires. Ever. They said fires were bad. They were bright and warm, melting and burning frozen, cold things. Everything Cosette yearned for, yet feared. Melting what was frozen Cosette figured was okay, but she was afraid of burning.

"Cosette?" She was shaken again. _Piper_ , she remembered. It was the pretty girl Piper from the camp for demigods talking. The one who knew French. Everyone was so nice there, Cosette was sure it must have been a dream. _Wait!_ If Piper was really here talking...then it all must be real!

Her eyes shot open. She was lying on the nice guy's cot in his cabin. The one who tried to greet her in French. John. Or maybe it was Jason. His accent was horrendous, but he did try.

She looked around to find Piper, Jason, and the blonde healer, Will, looking down at her.

Will asked something, but all Cosette got out of it was the word _you_. She looked to Piper for a translation.

"How are you feeling?"

Well, she did not feel like she was going to faint or throw up anytime soon. Her side was still throbbing, but the pain had dulled a bit. "Better," she answered.

"You feel like coming down to campfire? The others have already headed out."

Cosette nodded hesitantly. Maybe it was not as bad as Mother said. Piper and Will helped her to stand. Piper linked Cosette's arm through her own, something Cosette was grateful for. It looked completely normal, but it still gave her a way to lean on Piper. Will supported her on her other side. Like before, Jason held the door open for them.

Slowly but surely, the cross the campground to the amphitheater where the campfire was held. They sat on the top row where Leo had saved seats so Cosette did not have to climb all the way down and back up.

The sing-along had already started. A few of the Apollo kids had guiters, lyres, and flute up on stage, leading the singing. Cosette did not understand the words, but she cracked a small smile at it all, especially Leo, who over-exaggerated all of the motions that went with the songs.

"Well sung, demigods!" Chiron the centaur boomed when the singing was over. "We are happy to welcome our newest camper to our nightly festivities. Everyone, please make Cosette Grantham feel at home as she continues to heal."

Everyone clapped and a few cheered.

"Now, regarding tonight's-" Chiron was cut off by a blue-white light invading the amphitheater. All the campers turned to figure out where it was coming from and gasped.

A snowflake glowed brilliantly over Cosette's white head. Whispers broke out. They had never seen a symbol like this before.

Chiron was the first to recover from his shock. "Cosette, please come forward," he asked. Jason and Will carefully helped her down the sloped path to the front, with Piper following translator. "Cosette, which of your parents is mortal?"

"Papa," she answered when Piper translated his question for her. He nodded solemnly.

"Never before in all of known history has Boreas' daughter had a child, but if it is your mother who is divine, there is no other it could be," Chiron bowed to Cosette, and the other camper followed suit. "Hail, Cosette, daughter of Khione, goddess of snow and ice." The snowflake over her head flashed and her clothes were replaced with a white ancient Greek style gown that shimmered like new-fallen snow with pale ice blue frost patterns long the hem. A silver cord belt criss-crossed her slender torso from just under her chest to her waist. Her long wavy hair was pulled up into an ancient Greek ponytail style.

Leo sat at the top, stunned. _Ice Princess had a daughter?_ No wonder she had been giving him that judging look at dinner. Her mother probably told her about him! Wait, most demigods did not meet their godly parents until after they were claimed. Maybe she was like that because she knew he was a son of fire. Fire and ice do not mix. _At all._

But as she did her best to stand tall between Jason and Will, Leo could not help but notice things like how her ice blue eyes shone in the pale light, how porcelain-like her pale, unblemished skin appeared, or how tiny her waist was. Not that things like that mattered to him. He totally did not care that Cosette currently looked like a gorgeous, ancient Greek goddess version of Elsa from Frozen. He did not care one teeny bit...

A gust of freezing, Artic air rushed in and swirled around Cosette. She glowed white-blue for a moment, causing the boys to quickly step away. Then, the glow and the snowflake faded, leaving Cosette standing alone. She swayed slightly, but Will quickly caught her before she could fall. With Chiron's permission, he led her back up to their seats, Jason and Piper going behind them. Whatever the glowing was, it must have given her some strength, because she made back up to top without too much difficulty.

Chiron cleared his throat loudly to dispel the the last of the murmurs that followed Cosette back to her seat. "Ahem!...As I was saying before, Capture the Flag tonight! Teams, make your final preparations. The defending team may go hide their flag in the woods. Dismissed!"


End file.
